This invention relates to an improved optical connector to connect two pairs of optical fibers, or optical fibers and light-receiving or light-transmitting elements to each other simultaneously.
Recently, optical fibers have increasingly found application and have been widely employed in medical instruments. For example, in a medical instrument for spectral analysis of living body tissue, light is transmitted and received through optical fiber bundles to measure the spectral characteristics of the tissues under study. Such an instrument for spectral analysis of living body tissue is shown in FIG. 1, wherein a light-transmitting fiber 2 for transmitting light therethrough from a light source 1 in section 6', a light-receiving fiber 3 for receiving light from the living body tissues, and a light-transmitting and receiving fiber 4 for a contact switch is provided to determine the timing for taking data. A probe 5 having a fiber bundle is used.
It is necessary for the probe 5 to be capable of being easily demounted from a main body 6 and sterilized, since it is introduced into a living body cavity. For this reason, conventionally, the probe 5 has been provided with a divergent point 5a. At this divergent point 5a, the probe 5 is separated into the light-transmitting fiber bundle 2, the light-receiving fiber bundle 3, and the contact switching fiber bundle 4, which are provided with the respective connectors 7, 8, 9 and 10 at top ends thereof. With these connectors, the probe 5 is connected to the instrument main body 6 and 6'.
Therefore, the structure of the probe 5 becomes complicated, and its mechanical strength is weakened. This creates inconveniences in the production and/or use thereof and increases production costs.
In operation, light is received through a slit 11 positioned on the back of the light-receiving connector 8 of the main body portion 6 to perform a spectral analysis. The above-described instrument, however, has the disadvantage that the exchange of the slit, which is performed to change its resolving power and light reception, for example, can be achieved only with difficulty.
Referring again to FIG. 1, a light source section 6' and a spectral analysis section 6 of the main body of the spectral analysis system are separated from each other by a partition 6" so that transmitted and received light does not interfere with each other. The portions 6 and 6' are provided with female housings 7 and 8, respectively, of an optical connector assembly. When the male housings 12 and 12' are plugged in the female housings 7 and 8, respectively, light from a light source in the light source section 6' is concentrated on the end of the light-transmitting fiber by means of condensing lens 14 (having a fairly large diameter since it is necessary to concentrate a large quantity of light of about from 1 to 10 mw at the end of the light-transmitting fiber), and is sent through the light-transmitting fiber bundle 2 to a measuring point 15 where the tissue is illuminated. The light from the tissue is received through the light-receiving fiber bundle 3 on a slit 11 in the spectral analysis section 6 and, thereafter, analysis is performed by means of the spectral analysis system.
Another defect of the above-described prior art apparatus resides in that the fiber bundle 5 is separated into the light-transmitting fiber bundle 2 and the light-receiving fiber bundle 3 at the divergent point 5a. Specifically, this often causes problems such as fiber-cutting. Furthermore, since the female housing 7 for the light-transmitting fiber and the female housing 8 for the light-receiving fiber bundle should be provided separately in the main body of the analytical apparatus, the arrangement of the light source section 6' and the spectral analysis section 6 which should be placed as closely as possible is limited, preventing miniaturization of the apparatus.